What determines framerate?

[unp|dissy]

Hey Guys,

I've always considered core components (GPU/CPU/RAM) to determine framerate in 3d applications. Obviously poorly coded games are going to suffer from framerate issues than others (crysis perhaps?) But recently, playing counterstrike source, I started wondering.

Here below you can see I'm playing CSS on an AIM map, starting with an average of 200fps. Now as the game goes on, more and more people die / respawn, the body count in the map gets bigger, and my framerate starts to drop - makes sense right? (I ended up with 15-30FPS - I've got quite a decent machine ) More graphical entities = lower framerate, my hardware would be more stressed right?

http://s18.postimage.org/pbhkp16ig/aim_map_usp0002.jpg

Well, wrong! At the the I had a few apps monitoring component stress on my system, GPU-Z, Windows Performance Mon, taskman, and they all seemed okay..

http://s13.postimage.org/m105f7ndi/Untitled.jpg

GPU is around 50% load, for clock and memory. CPU and RAM are near here or there, and disk IO is idle.

Confused as to what's causing the fps drops when such things happen? I'd of expected at least one part of my components to be maxed out, but I can't find it.

Perhaps I've missed something and you guys can put me right? OR maybe it's just simply down to a poorly written part of the games code?

Cheers

 

[Marine-RX179]

It's down to the balancing between graphic card and CPU. Typically in the older games, even entry level gaming cards like 6850/GTX460 can max them out with ease, but in those older games they only tend to use 1-2 cores, so the CPU might not be able to scale shoulder to shoulder with the graphic card, thus the frame rate drop.

With that said, standard monitors would only deplay up to 60fps max for 1920 res, so as long as the frame rate remain constant at 60fps, I don't think it matters too much whether of not if CPU and graphic card bottleneck one another or not.

But strictly speaking, for source games its frame rate is more dependent on CPU performance than graphic's.

 

[sadbuttrue]

The GPU load value is never accurate. It only really shows how much of the GPUs total reources are in use. If you run at maximum detail you may hit "100%" load, but run at lower detail and it'll show 50% load. The card is still likely taking the same amount of time to generate each frame.

 

[unp|dissy]

It's down to the balancing between graphic card and CPU. Typically in the older games, even entry level gaming cards like 6850/GTX460 can max them out with ease, but in those older games they only tend to use 1-2 cores, so the CPU might not be able to scale shoulder to shoulder with the graphic card, thus the frame rate drop.

With that said, standard monitors would only deplay up to 60fps max for 1920 res, so as long as the frame rate remain constant at 60fps, I don't think it matters too much whether of not if CPU and graphic card bottleneck one another or not.

But strictly speaking, for source games its frame rate is more dependent on CPU performance than graphic's.

I agree with some points. 60fps required for standard monitors these days (however I only play games at 120hz ), software utilization of only 1-2 cores (especially in older games) and that's what could be causing the FPS drop. I can't see my CPU getting stressed though, it's load is literally non existing, and this CPU (Xeon E5530) should be able to handle without breaking a sweat.

Don't get me wrong, I'm not after performance increase (I'm upgrading some components this week anyway) I'm just generally interested into what maybe causing bottlenecks in systems, in order to improve that aspect of a machine.

If somebody asked me this question that I posted, I wouldn't of been able to answer!

 

[unp|dissy]

The GPU load value is never accurate. It only really shows how much of the GPUs total reources are in use. If you run at maximum detail you may hit "100%" load, but run at lower detail and it'll show 50% load. The card is still likely taking the same amount of time to generate each frame.

Ah, so there may be an aspect of the GPU that's under resourced, however another aspect of the GPU completely maxed out - bringing the load average to a 50% margin?

That's interesting..

How would one determine that as a bottleneck though, should say, somebody ask me what part of their system to upgrade, if this framerate was causing a problem for them? I wouldn't have a clue what to advise!

 

[Marine-RX179]

I agree with some points. 60fps required for standard monitors these days (however I only play games at 120hz ), software utilization of only 1-2 cores (especially in older games) and that's what could be causing the FPS drop. I can't see my CPU getting stressed though, it's load is literally non existing, and this CPU (Xeon E5530) should be able to handle without breaking a sweat.

Don't get me wrong, I'm not after performance increase (I'm upgrading some components this week anyway) I'm just generally interested into what maybe causing bottlenecks in systems, in order to improve that aspect of a machine.

If somebody asked me this question that I posted, I wouldn't of been able to answer!

For non-graphic demand games on 120Hz monitor, it would most likely be more depened on CPU side. GPU not at max load is the most apparent incidicater for CPU bottleneck.

As for CPU not under lots of load, that's most likely because 2-3 cores are not being used. Yes CPU usage would show it got workload spreaded across the 4 cores, but if you add up total % of CPU usage spreaded across the 4 cores, in games that run in two thread it tend to never exceed a total of 200%, regardless of what CPU it is...may it be Q6600, or i5 3570K.

 

[unp|dissy]

For non-graphic demand games on 120Hz monitor, it would most likely be more depened on CPU side. GPU not at max load is the most apparent incidicater for CPU bottleneck.

As for CPU not under lots of load, that's most likely because 2-3 cores are not being used. Yes CPU usage would show it got workload spreaded across the 4 cores, but if you add up total % of CPU usage spreaded across the 4 cores, in games that run in two thread it tend to never exceed a total of 200%.

That's a lot more clearer. Thank you :]